Paralympics athlete Oscar Pistorius took the witness stand at his murder trial in Pretoria, South Africa, today. Pistorius is charged with premeditated murder in the shooting death of his girlfriend, Reeva Steenkamp, a year ago. He claims he mistook her for an intruder when he shot her through a bathroom door in his home. Testifying in his own defense today, Pistorius began by offering an emotional apology to the Steenkamp family.

OSCAR PISTORIUS: I wake up every morning and you're the first people I think of, the first people I pray for. I can't imagine the pain and the sorrow and the emptiness that I've caused you and your family. And I was simply trying to protect Reeva. I can promise that when she went to bed that night she felt loved.

BLOCK: David Smith was in the courtroom today. He's covering the Pistorius trial for The Guardian newspaper. David, welcome to the program.

DAVID SMITH: Thank you.

BLOCK: Well, aside from that apology, much of Oscar Pistorius's testimony today seemed to be not about what happened on that night that he shot Reeva Steenkamp, but on his own trauma since the shooting.

SMITH: That's right. After the apology, Oscar Pistorius spoke about the effects that the tragedy of a year ago had on him. And he described terrible nightmares, waking up thinking that he could smell blood. And he described one incident where he woke up in a panic and actually climbed into a cupboard, because he was frightened and phoned his sister.

All in all, it seemed to be building a picture as the defense wanted of someone so very sympathetic, a whole different side to his character compared to what we've been hearing about, you know, hotheaded, irresponsible behavior and some of the unflattering things his girlfriend said about him.

BLOCK: Well, the testimony adjourned early today and I know Oscar Pistorius will be back on the stand. What do you expect when he's cross examined?

SMITH: Well, that's what many people are waiting for really. It will be a very different when the prosecutor, Gerrie Nel, begins to cross-examine him. You know, clearly, Pistorius, as we saw today on the witness stand, very fragile, very prone to breaking down in tears. How he will stand up to quite a ferocious cross examination really remains to be seen.

BLOCK: And if Pistorius is convicted of premeditated murder, what is the sentence he would face?

SMITH: Well, it's officially a minimum of 25 years and could be longer, a full life sentence. One of the question harboring in the background of this trial is whether there'll be some kind of special dispensation for him, because your typical South African prison is probably not set out, firstly, for such a famous celebrity, but secondly for a man whose legs were amputated when he was 11 about months old, and he uses prosthetic limbs.

BLOCK: You've been covering the trial for some time. As you think about the case that the prosecution has laid out first, and now it's turned to the defense, does it strike you that the prosecution has laid out a compelling argument that would lead to Oscar Pistorius's conviction? Or is there room for the defense to really poke holes in that?

SMITH: I think the defense does have room. I think many people would question whether the prosecution really managed to prove, beyond reasonable doubt, that Pistorius knowingly killed his girlfriend. The prosecution evidence, some would say, you know, lacked a complete sort of narrative thread. Perhaps most damaging for Pistorius was sort of neighbors who heard screams. And that could suggest that he had an argument with Reeva Steenkamp. But I mean the defense will claim that what they heard was Pistorius himself screaming.

There were also...

BLOCK: When he realized what he had done, in other words.

SMITH: Yes. You know, his version of events that he mistook her for an intruder and shot because, as he said today, you know, he was trying to protect Reeva, that is still in play. It has not been disproven. And, you know, is perhaps almost believable on the basis of his own paranoia about crime and the situation in South Africa generally.

BLOCK: David Smith of The Guardian newspaper is covering the murder trial of Oscar Pistorius in Pretoria, South Africa. David, thank you.